JP3264027B2 - Discharge cell and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a discharge cell incorporated in a plasma addressed display or the like and a method for manufacturing the same. More specifically, the present invention relates to an electrode structure of a discharge cell having a linear discharge channel and a method for forming the same.

[0002]

2. Description of the Related Art A plasma addressed display device incorporating a discharge cell having a linear discharge channel is known, and is disclosed, for example, in Japanese Patent Application Laid-Open No. 4-265931. In order to clarify the background of the present invention, a conventional structure will be briefly described with reference to FIG. The plasma addressed display device has a structure in which a display cell 51 and a discharge cell 52 and an intermediate substrate 53 interposed therebetween are stacked. Display cell 51
Is formed using an upper glass substrate 54, and a plurality of signal electrodes D are formed in parallel on the inner main surface thereof in the column direction. The glass substrate 54 is a spacer 5
5 and is adhered to the intermediate substrate 53 via a predetermined gap. The gap is filled with a liquid crystal layer 56. On the other hand, the discharge cells 52 are configured using a lower glass substrate 57. On the inner main surface of the substrate 57, a plasma electrode 58 extending in the row direction orthogonal to the signal electrode D is formed.
The plasma electrode 58 functions alternately as an anode A and a cathode K. A partition wall 59 is formed along the plasma electrode 58. The top of the partition wall 59 is in contact with the intermediate substrate 53 and serves as a spacer. The lower glass substrate 57 is bonded to the intermediate substrate 53 using a sealing material 60. A hermetically sealed space is formed between the two. This space is divided by stripe-shaped partition walls 59, and constitutes discharge channels 61 individually serving as row scanning units. Each of the discharge channels 61 is filled with an ionizable gas.

FIG. 6 is a schematic perspective view showing an electrode structure of a conventional discharge cell. An electrode 102 patterned in a stripe pattern is formed on the surface of a substrate 101. The plurality of stripe electrodes 102 are arranged at a pitch P and each have a width dimension W1. A partition 103 is formed on each stripe electrode 102. The plurality of striped partition walls 103 are also arranged at the same pitch P, and each width dimension W2 is
Is set smaller than the width dimension W1.

[0004]

Problems to be solved by the invention will be described with reference to FIG. 7 showing a state in which a pitch shift has occurred in FIG. The stripe pattern shown in FIG. 7 is generally formed using a mask. The electrodes 102 and the partition walls 103 originally have the same pattern arrangement pitch P, but have different width dimensions W1 and W2. Therefore, different masks are used for forming the electrode 102 and the mask used for forming the partition 103 in the related art. In this case, both masks have the same stripe pattern pitch and are precisely aligned with each other to align electrode 102 and partition 103 with each other.

A thick film printing method using a screen mask is usually used for forming electrodes and partition walls. The screen mask is formed by attaching a screen mesh to a frame with tension. Photolithography is applied to the screen mesh to which the photosensitive agent has been applied to form a predetermined mask pattern. However, due to the tension, it is difficult to set the pitch P of the stripe pattern completely different between different screen masks, and in fact, a certain pitch error ΔP is included. In addition, when performing thick-film printing, pressure is applied to the screen mask by the squeegee to deform it. The degree of deformation is slightly different depending on each screen mask, and the pitch of the actually printed stripe pattern is deviated from the target value. For this reason, it is practically difficult to accurately match the lower electrode 102 and the upper partition 103 with a problem that a so-called pitch shift occurs.

[0006] If there is a relative displacement between the electrode and the partition, there arises a problem that the operation of the discharge cell becomes unstable. This point will be briefly described with reference to specific dimensions with reference to FIG. (A) shows a state where there is no displacement. The plasma electrodes 151 function alternately as anodes A and cathodes K and are arranged on the substrate 152 at a pitch of, for example, 410 μm. A partition 153 is formed on each plasma electrode. The width of the partition is set to 120 μm, and the width of the plasma electrode 151 is set to 300 μm. A linear discharge channel 154 is formed between adjacent partition walls 153, and a part of the anode A and a part of the cathode K are exposed inside. When a predetermined voltage is applied between both electrodes, plasma discharge occurs. In order to stably maintain this plasma discharge, it is necessary to secure a constant electrode exposure area. In particular, the exposed area of the cathode K is dominant,
It is necessary to secure an electrode exposure width of at least 60 μm. At this time, assuming that the alignment error between the partition 153 and the electrode 151 is about ± 30 μm at the maximum, it is necessary to secure an electrode exposure width of at least 90 μm on both sides of the partition 153 as shown in the figure. Therefore, in the illustrated example, the electrode width is set to 30.
The width is set to 0 μm, and the partition width is set to 120 μm.
As a result, the opening width between the adjacent anode A and cathode K becomes only 110 μm, and the contrast is sacrificed as a display device. (B) is 30
This shows a state in which a displacement of μm has occurred. In this case, in the discharge channel 155, the exposed width of the cathode K is a required minimum of 60 μm. If the displacement is further increased, the plasma discharge in the discharge channel 155 becomes extremely unstable. On the other hand, in the adjacent discharge channel 154, the exposed width of the cathode K is increased to 120 μm, and a stable plasma discharge is obtained. Like this
In the conventional structure, when a displacement occurs between the partition and the electrode, the plasma intensity of the discharge channel varies alternately, and thus there is a problem that the image quality is impaired when viewed as a whole display device.

[0007]

In view of the above-mentioned problems of the prior art, the present invention provides an electrode capable of maintaining a stable plasma discharge even when a relative displacement occurs between a plasma electrode and a partition. The purpose is to provide the structure. The following measures were taken to achieve this purpose. That is, the discharge cell according to the present invention comprises, as basic components, one substrate, stripe-shaped anodes and cathodes alternately arranged thereon at a predetermined interval, and the one substrate via a predetermined gap. and the other substrate was bonded to, interposed and given between between the substrates
Partition walls which are arranged in stripes at intervals to define the gaps and form discharge channels. As a feature, before
The striped partition is also only striped anode
The anode is disposed immediately below the partition wall and has a width dimension wider than the width dimension of the partition wall, while the cathode is disposed in the middle of the adjacent partition wall and between the anode and the anode.
Generates plasma discharge . Further, the method of manufacturing a discharge cell according to the present invention includes a step of alternately printing and forming an anode and a cathode each having a predetermined width on a surface of one of the substrates in a stripe shape at a predetermined interval; It consists of a step of printing a partition having a narrower width over only the anode at a predetermined interval, and a step of joining the other substrate via the partition and sealing an ionizable gas between the two substrates. The discharge cell having the above-described structure or the discharge cell created by the above-described manufacturing method can be incorporated in, for example, a plasma addressed display device. In this case, as a basic configuration requirement, the plasma addressed display device includes a flat display cell having a plurality of signal electrodes arranged in a column direction and a discharge cell having a plurality of discharge channels arranged in a row direction. It has a panel structure. As a feature, the discharge channel has a stripe-shaped anode formed on the substrate, a stripe-shaped cathode formed between the anodes, and a width dimension smaller than the width dimension of each anode, and is aligned with each anode. And the partition walls formed by the above method.

[0008]

According to the present invention, the cathode is disposed in the middle of the adjacent partition wall and is entirely exposed. Therefore, even if a relative displacement occurs between the plasma electrode and the partition, there is usually no extreme state in which the partition extends to the region of the cathode, so that the cathode is not affected at least. As a result, the exposed area of the cathode which is dominant in the plasma discharge can be ensured regardless of the displacement, so that the stability of the plasma discharge can be improved. On the other hand, since the anode is arranged immediately below the partition, it is partially exposed on both sides thereof. Therefore, if a relative displacement occurs between the plasma electrode and the partition, the exposed width of the anode is biased. However, since the anode only needs to be able to discharge electric charges, it is only necessary to secure a certain exposed area, and the deviation of the exposed area does not significantly affect the plasma discharge stability.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic diagram showing a basic structure of a discharge cell according to the present invention. As shown in FIG. 1A, the discharge cell has a flat panel structure including one substrate 1 and the other substrate 2 facing the one substrate 1 via a predetermined gap. The two substrates 1 and 2 are hermetically joined to each other via a sealing material 3. On the lower substrate 1, striped anodes A and cathodes K are alternately arranged. A partition 4 is interposed between the substrates 1 and 2. The barrier ribs 4 are arranged in a stripe pattern to define voids and form discharge channels 5. An ionizable gas is sealed in the discharge channel 5. The anode A is disposed immediately below the partition 4 and has a width larger than the width of the partition 4. Therefore, the central portion of the anode A is covered with the partition wall 4 while the side edges are exposed. The cathode K is arranged in the middle of the adjacent partition wall 4 and is entirely exposed in the discharge channel 5. A plasma discharge is generated by applying a predetermined voltage between the anode A and the cathode K exposed in each discharge channel 5.

A discharge cell having such a structure can be manufactured by the following steps. First, anodes A and cathodes K each having a predetermined width are alternately printed in a stripe pattern at a predetermined interval on the surface of one substrate 1. Next, anode A
The partition wall 4 having a width smaller than the width dimension is printed on the anode A alone. Finally, the upper substrate 2 is hermetically bonded via the partition wall 4, and an ionizable gas is sealed between the two substrates.

Next, a specific pattern dimensional relationship will be exemplarily described with reference to FIG. For ease of comparison with the conventional example shown in FIG. 8A, the plasma electrode arrangement pitch is set to 410 μm in this embodiment as well. Further, the width of the opening provided between the middle cathode K and the anodes A on both sides is also set to 55 μm each, and a total of FIG.
Is set to be 110 μm, which is equal to the conventional example shown in FIG. In this relation, the width of the anode A is 220 μm, and the width of the cathode K is 80 μm. Therefore, the exposure width of the cathode K is 60 μm or more, which is the minimum required for plasma discharge. On the other hand, the width of the partition 4 is set to 120 μm,
An exposed width of the anode A of 50 μm is secured on each side.

FIG. 2B shows a state in which a displacement of 50 μm has occurred in the right direction in the drawing from the alignment state shown in FIG. In this case, the exposure width of the cathode K does not change at all, and the opening width does not decrease. The exposed width of the anode A is 0 μm on one side and is enlarged to 100 μm on the other side, and is kept constant as a whole in the discharge channel. In this way, even if the partition wall is displaced by 50 μm at the maximum, the discharge current is kept constant since the surface area of the cathode K is not affected. On the other hand, since the anode A only needs to be capable of discharging electric charges, it is sufficient to secure a predetermined surface area as a whole for one cathode K. In this example, if the surface area of the anode A on the left side with respect to a certain cathode K decreases, the surface area on the right side increases accordingly, and the entire area is kept constant. As described above, in the conventional structure, the allowable range of the positional deviation is ± 30 μm, but in the present invention, even if the positional deviation is approximately ± 50 μm, there is no adverse effect on the discharge characteristics and the aperture ratio. Has been greatly improved.

FIG. 2C shows a state in which the partition walls of the 105 μm are displaced from the alignment state shown in FIG.
Also in this case, the exposed surface area of the cathode K is not affected, and the exposed surface area of the anode A is maintained at a predetermined value or more . However, the dimension of the opening width is reduced because the left portion in the drawing is blocked by the partition wall 4.

FIG. 4D shows a state in which a displacement of 125 μm has occurred from the alignment state shown in FIG. In this case, the surface of the cathode K is partially covered with the partition 4, but the exposed width of 60 μm is still secured. Therefore, stable plasma discharge can be maintained.
Thus, as far as the stability of plasma discharge is concerned, ± 1
A positional deviation of up to 25 μm can be allowed. Conversely, if the error range of the displacement is controlled to ± 30 μm as in the conventional example,
The aperture ratio can be increased accordingly.

Next, an embodiment of a plasma addressed display device incorporating a discharge cell according to the present invention will be described with reference to FIG. This plasma addressed display device has a flat panel structure in which display cells 11 and discharge cells 12 and a common intermediate substrate 13 made of an extremely thin dielectric sheet interposed between the display cells 11 and the discharge cells 12 are stacked. The display cell 11 is configured using an upper glass substrate 14, and a plurality of signal electrodes D made of a transparent conductive film are formed on the inner main surface thereof in parallel with each other along the column direction. The glass substrate 14 is bonded to the intermediate substrate 13 with a predetermined gap using a spacer 15. The gap is filled with a liquid crystal layer 16.

On the other hand, the discharge cells 12 are provided on the lower glass substrate 17.
It is configured using An anode A and a cathode K are alternately formed on the inner main surface of the substrate 17 in the row direction.
Further, a partition wall 18 is formed along the anode A. The top of the partition wall 18 is in contact with the intermediate substrate 13 and serves as a spacer. The lower glass substrate 17 is bonded to the intermediate substrate 13 using a sealing material 19. A hermetically sealed space is formed between the two. This gap is divided or partitioned by the partition wall 18 and individually constitutes the discharge channel 20 to be a unit of row scanning. That is, each discharge channel 20 has a pair of anodes A formed in parallel on the substrate 17 and one cathode K formed between them.
And a pair of partition walls 18 having a width smaller than the width of each anode A and formed in alignment with each anode A. An ionizable gas is sealed in the airtight discharge channel 20. The gas type can be selected from, for example, helium, neon, argon, or a mixed gas thereof.

Finally, the operation of the plasma addressed display device will be briefly described for reference with reference to FIG. This drawing shows an example of a driving circuit used for a display device. This drive circuit includes a signal circuit 21, a scanning circuit 22, and a control circuit 23. Signal electrodes D1 to Dm are connected to the signal circuit 21 via a buffer. On the other hand, the scanning circuit 22 also has cathodes K1 through K
n are connected. The anodes A1 to An are commonly grounded. The cathode is line-sequentially scanned by the scanning circuit 22, and the signal circuit 21 supplies an analog image signal to each signal electrode in synchronization with the scanning. The control circuit 23 controls the synchronization between the signal circuit 21 and the scanning circuit 22.
A discharge channel is formed along each cathode to form a row scanning unit. On the other hand, each signal electrode is a column drive unit. A pixel 24 is defined between the two units.

FIG. 4 is a schematic diagram showing two pixels 24 shown in FIG. 3 cut out. Each pixel 24 includes a sampling capacitor including the liquid crystal layer 16 sandwiched between the signal electrodes D1 and D2 and the intermediate substrate 13, and a series connection of a plasma sampling switch S1. The plasma sampling switch S1 equivalently represents the function of the discharge channel. That is, when the discharge channel is activated, the inside thereof is almost entirely connected to the anode potential. On the other hand, when the plasma discharge ends, the discharge channel becomes a floating potential. An analog image signal is written into the sampling capacitor of each pixel 24 via the sampling switch S1 to perform a so-called sampling hold. The gradational lighting or extinguishing of the pixel 24 can be controlled by the level of the analog image signal.

[0019]

As described above, according to the present invention, in a discharge cell having a straight discharge channel, the anode is disposed immediately below the partition wall, and is wider than the partition wall to make the surface of the anode larger. Partially exposed. On the other hand, the cathode is arranged in the middle of the adjacent partition wall, and the surface is entirely exposed. With such a configuration, the relative positional deviation tolerance of the partition wall with respect to the plasma electrode is increased, so that the production of the discharge cell is facilitated, and there is an effect that it is possible to cope with an increase in size and definition. In addition, since stable plasma discharge operation is possible, there is an effect that image quality is improved when viewed as a display device. Furthermore, in the case of manufacturing a discharge cell with the same degree of positional deviation tolerance as the conventional one, the aperture ratio can be increased, so that high image quality can be achieved and the backlight can be reduced in power. is there.

[Brief description of the drawings]

FIG. 1 is a schematic partial sectional view showing a structure of a discharge cell according to the present invention.

FIG. 2 is a schematic cross-sectional view showing one example of a plasma addressed display device assembled using the discharge cells according to the present invention.

FIG. 3 is a block diagram showing a driving circuit of the plasma addressed display device shown in FIG.

FIG. 4 is a schematic diagram showing the pixel shown in FIG. 3 cut out.

FIG. 5 is a cross-sectional view illustrating an example of a plasma addressed display device incorporating a conventional discharge cell.

FIG. 6 is a perspective view showing a conventional discharge cell electrode structure.

FIG. 7 is a perspective view illustrating a problem of a conventional method of manufacturing a discharge cell.

FIG. 8 is a schematic diagram for explaining a structural problem of a conventional discharge cell.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Substrate 4 Partition wall 5 Discharge channel A anode K cathode

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01J 17/04 G02F 1/1333 H01J 9/02 H01J 17/49 G02F 1/133 505

Claims (4)

(57) [Claims] 1. A substrate, a striped anode and a cathode alternately arranged on the substrate at a predetermined interval, and the other substrate bonded to the one substrate via a predetermined gap. And a partition interposed between the two substrates and arranged in a stripe pattern at a predetermined interval to partition the gap to form a discharge channel, wherein the stripe-shaped partition is also a stripe-shaped partition. Anode
Is formed to overlap the body, it said anode has a wider width dimension than the width dimension of the arranged and the partition wall just below the said partition wall, characterized in that said cathode is located in the middle of the adjacent barrier ribs Discharge cell. 2. A process for each print formed in stripes at a predetermined interval anode and cathode alternately with a predetermined width on one surface of the substrate, the partition wall having a narrow width dimension than the width dimension of the anode A method for manufacturing a discharge cell, comprising: a step of printing by overlapping only an anode at a predetermined interval ; and a step of bonding the other substrate through the partition and filling an ionizable gas between the two substrates. 3. A plasma addressed display device having a flat panel structure in which a display cell having a plurality of signal electrodes arranged in a column direction and a discharge cell having a plurality of discharge channels arranged in a row direction are overlapped with each other. The discharge channel has a stripe-shaped anode formed on the substrate, a stripe-shaped cathode formed between the anodes, and a width smaller than the width of each anode, and is formed in alignment with each anode. A plasma addressed display device comprising a partition wall. 4. An individual discharge channel comprising: a pair of anodes;
4. The plasma addressed display device according to claim 3, comprising one cathode located between these and a pair of partition walls aligned with each anode.